Scientific World Journal
Bacterial Proteins/genetics, Bacterial proteins/metabolism, Coculture techniques/methods, Gene expression regulation, Bacterial, Gene expression regulation enzymologic, Genes bacterial, Oxidoreductases/genetics, Oxidoreductases/metabolism, Pseudomonas aeruginosa/enzymology, Pseudomonas aeruginosa/genetics, Pyocyanine/genetics, Pyocyanine/metabolism, Quorum sensing, RNA, Bacterial/genetics, Real-time polymerase chain reaction, Roseobacter/enzymology, Roseobacter/genetics, Thiosulfate sulfurtransferase/genetics, Thiosulfate sulfurtransferase/metabolism, beta-lactamases/genetics, beta-lactamases/metabolism
Consistent biosynthesis of desired secondary metabolites (SMs) from pure microbial cultures is often unreliable. In a proof-ofprinciple study to induce SM gene expression and production, we describe mixed “co-culturing” conditions and monitoring of messages via quantitative real-time PCR (qPCR). Gene expression of model bacterial strains (Pseudomonas aeruginosa PAO1 and Roseobacter denitrificans Och114) was analyzed in pure solo and mixed cocultures to infer the effects of interspecies interactions on gene expression in vitro, Two P. aeruginosa genes (PhzH coding for portions of the phenazine antibiotic pathway leading to pyocyanin (PCN) and the RhdA gene for thiosulfate: cyanide sulfurtransferase (Rhodanese)) and two R. denitrificans genes (BetaLact formetallo-beta-lactamase and the DMSP gene for dimethylpropiothetin dethiomethylase) were assessed for differential expression. Results showed that R. denitrificans DMSP and BetaLact gene expression became elevated in a mixed culture. In contrast, P. aeruginosa co-cultures with R. denitrificans or a third species did not increase target gene expression above control levels. This paper provides insight for better control of target SM gene expression in vitro and bypass complex genetic engineering manipulations.
Conway, C. A., N. Esiobu, and J. V. Lopez. 2012. "Co-cultures of Pseudomonas aeruginosa and Roseobacter denitrificans reveal shifts in gene expression levels compared to solo cultures." ScientificWorldJournal no. 2012:120108. doi: 10.1100/2012/120108.